PIC(1) PIC(1)
NAME
pic - compile pictures for troff or TeX
SYNOPSIS
ppiicc [ -nnvvCCSSUU ] [ filename ... ]
ppiicc -tt [ -ccvvzzCCSSUU ] [ filename ... ]
DESCRIPTION
This manual page describes the GNU version of ppiicc, which is part of the
groff document formatting system. ppiicc compiles descriptions of pic-
tures embedded within ttrrooffff or TeX input files into commands that are
understood by TeX or ttrrooffff. Each picture starts with a line beginning
with ..PPSS and ends with a line beginning with ..PPEE. Anything outside of
..PPSS and ..PPEE is passed through without change.
It is the user's responsibility to provide appropriate definitions of
the PPSS and PPEE macros. When the macro package being used does not sup-
ply such definitions (for example, old versions of -ms), appropriate
definitions can be obtained with -mmppiicc: These will center each picture.
OOPPTTIIOONNSS
Options that do not take arguments may be grouped behind a single -.
The special option -- can be used to mark the end of the options. A
filename of - refers to the standard input.
-CC Recognize ..PPSS and ..PPEE even when followed by a character other
than space or newline.
-SS Safer mode; do not execute sshh commands. This can be useful when
operating on untrustworthy input. (enabled by default)
-UU Unsafe mode; revert the default option -SS.
-nn Don't use the groff extensions to the troff drawing commands.
You should use this if you are using a postprocessor that
doesn't support these extensions. The extensions are described
in ggrrooffffoouutt(5). The -nn option also causes ppiicc not to use zero-
length lines to draw dots in troff mode.
-tt TeX mode.
-cc Be more compatible with ttppiicc. Implies -tt. Lines beginning with
\\ are not passed through transparently. Lines beginning with ..
are passed through with the initial .. changed to \\. A line
beginning with ..ppss is given special treatment: it takes an
optional integer argument specifying the line thickness (pen
size) in milliinches; a missing argument restores the previous
line thickness; the default line thickness is 8 milliinches.
The line thickness thus specified takes effect only when a non-
negative line thickness has not been specified by use of the
tthhiicckknneessss attribute or by setting the lliinneetthhiicckk variable.
-vv Print the version number.
-zz In TeX mode draw dots using zero-length lines.
The following options supported by other versions of ppiicc are ignored:
-DD Draw all lines using the \D escape sequence. ppiicc always does
this.
-TT dev Generate output for the ttrrooffff device dev. This is unnecessary
because the ttrrooffff output generated by ppiicc is device-independent.
UUSSAAGGEE
This section describes only the differences between GNU ppiicc and the
original version of ppiicc. Many of these differences also apply to newer
versions of Unix ppiicc. A complete documentation is available in the
file
//uussrr//sshhaarree//ddoocc//ggrrooffff//11..1199..11//ppiicc..mmss
TTeeXX mmooddee
TeX mode is enabled by the -tt option. In TeX mode, ppiicc will define a
vbox called \\ggrraapphh for each picture. Use the ffiiggnnaammee command to change
the name of the vbox. You must yourself print that vbox using, for
example, the command
\\cceenntteerrlliinnee{{\\bbooxx\\ggrraapphh}}
Actually, since the vbox has a height of zero (it is defined with
\vtop) this will produce slightly more vertical space above the picture
than below it;
\\cceenntteerrlliinnee{{\\rraaiissee 11eemm\\bbooxx\\ggrraapphh}}
would avoid this.
To make the vbox having a positive height and a depth of zero (as used
e.g. by LaTeX's ggrraapphhiiccss..ssttyy), define the following macro in your docu-
ment:
\\ddeeff\\ggppiiccbbooxx##11{{%%
\\vvbbooxx{{\\uunnvvbbooxx\\ccssnnaammee ##11\\eennddccssnnaammee\\kkeerrnn 00pptt}}}}
Now you can simply say \\ggppiiccbbooxx{{ggrraapphh}} instead of \box\graph.
You must use a TeX driver that supports the ttppiicc specials, version 2.
Lines beginning with \\ are passed through transparently; a %% is added
to the end of the line to avoid unwanted spaces. You can safely use
this feature to change fonts or to change the value of \\bbaasseelliinneesskkiipp.
Anything else may well produce undesirable results; use at your own
risk. Lines beginning with a period are not given any special treat-
ment.
CCoommmmaannddss
ffoorr variable == expr1 ttoo expr2 [bbyy [**]expr3] ddoo X body X
Set variable to expr1. While the value of variable is less than
or equal to expr2, do body and increment variable by expr3; if
bbyy is not given, increment variable by 1. If expr3 is prefixed
by ** then variable will instead be multiplied by expr3. X can
be any character not occurring in body.
iiff expr tthheenn X if-true X [eellssee Y if-false Y]
Evaluate expr; if it is non-zero then do if-true, otherwise do
if-false. X can be any character not occurring in if-true. Y
can be any character not occurring in if-false.
pprriinntt arg...
Concatenate the arguments and print as a line on stderr. Each
arg must be an expression, a position, or text. This is useful
for debugging.
ccoommmmaanndd arg...
Concatenate the arguments and pass them through as a line to
troff or TeX. Each arg must be an expression, a position, or
text. This has a similar effect to a line beginning with .. or
\\, but allows the values of variables to be passed through.
sshh X command X
Pass command to a shell. X can be any character not occurring
in command.
ccooppyy ""filename""
Include filename at this point in the file.
ccooppyy [""filename""] tthhrruu X body X [uunnttiill ""word""]
ccooppyy [""filename""] tthhrruu macro [uunnttiill ""word""]
This construct does body once for each line of filename; the
line is split into blank-delimited words, and occurrences of $$i
in body, for i between 1 and 9, are replaced by the i-th word of
the line. If filename is not given, lines are taken from the
current input up to ..PPEE. If an uunnttiill clause is specified, lines
will be read only until a line the first word of which is word;
that line will then be discarded. X can be any character not
occurring in body. For example,
..PPSS
ccooppyy tthhrruu %% cciirrccllee aatt (($$11,,$$22)) %% uunnttiill ""EENNDD""
11 22
33 44
55 66
EENNDD
bbooxx
..PPEE
is equivalent to
..PPSS
cciirrccllee aatt ((11,,22))
cciirrccllee aatt ((33,,44))
cciirrccllee aatt ((55,,66))
bbooxx
..PPEE
The commands to be performed for each line can also be taken
from a macro defined earlier by giving the name of the macro as
the argument to tthhrruu.
rreesseett
rreesseett variable1[,,] variable2 ...
Reset pre-defined variables variable1, variable2 ... to their
default values. If no arguments are given, reset all pre-
defined variables to their default values. Note that assigning
a value to ssccaallee also causes all pre-defined variables that con-
trol dimensions to be reset to their default values times the
new value of scale.
pplloott expr [""text""]
This is a text object which is constructed by using text as a
format string for sprintf with an argument of expr. If text is
omitted a format string of ""%%gg"" is used. Attributes can be
specified in the same way as for a normal text object. Be very
careful that you specify an appropriate format string; ppiicc does
only very limited checking of the string. This is deprecated in
favour of sspprriinnttff.
variable ::== expr
This is similar to == except variable must already be defined,
and expr will be assigned to variable without creating a vari-
able local to the current block. (By contrast, == defines the
variable in the current block if it is not already defined
there, and then changes the value in the current block only.)
For example, the following:
..PPSS
xx == 33
yy == 33
[[
xx ::== 55
yy == 55
]]
pprriinntt xx "" "" yy
..PPEE
prints 55 33.
Arguments of the form
X anything X
are also allowed to be of the form
{{ anything }}
In this case anything can contain balanced occurrences of {{ and }}.
Strings may contain X or imbalanced occurrences of {{ and }}.
EExxpprreessssiioonnss
The syntax for expressions has been significantly extended:
x ^^ y (exponentiation)
ssiinn((x))
ccooss((x))
aattaann22((y,, x))
lloogg((x)) (base 10)
eexxpp((x)) (base 10, ie 10^x)
ssqqrrtt((x))
iinntt((x))
rraanndd(()) (return a random number between 0 and 1)
rraanndd((x)) (return a random number between 1 and x; deprecated)
ssrraanndd((x)) (set the random number seed)
mmaaxx((e1,, e2))
mmiinn((e1,, e2))
!!e
e1 &&&& e2
e1 |||| e2
e1 ==== e2
e1 !!== e2
e1 >>== e2
e1 >> e2
e1 <<== e2
e1 << e2
""str1"" ==== ""str2""
""str1"" !!== ""str2""
String comparison expressions must be parenthesised in some contexts to
avoid ambiguity.
OOtthheerr CChhaannggeess
A bare expression, expr, is acceptable as an attribute; it is equiva-
lent to dir expr, where dir is the current direction. For example
lliinnee 22ii
means draw a line 2 inches long in the current direction. The `i' (or
`I') character is ignored; to use another measurement unit, set the
scale variable to an appropriate value.
The maximum width and height of the picture are taken from the vari-
ables mmaaxxppsswwiidd and mmaaxxppsshhtt. Initially these have values 8.5 and 11.
Scientific notation is allowed for numbers. For example
xx == 55ee-22
Text attributes can be compounded. For example,
""ffoooo"" aabboovvee lljjuusstt
is legal.
There is no limit to the depth to which blocks can be examined. For
example,
[[AA:: [[BB:: [[CC:: bbooxx ]]]]]] wwiitthh ..AA..BB..CC..ssww aatt 11,,22
cciirrccllee aatt llaasstt [[]]..AA..BB..CC
is acceptable.
Arcs now have compass points determined by the circle of which the arc
is a part.
Circles, ellipses, and arcs can be dotted or dashed. In TeX mode
splines can be dotted or dashed also.
Boxes can have rounded corners. The rraadd attribute specifies the radius
of the quarter-circles at each corner. If no rraadd or ddiiaamm attribute is
given, a radius of bbooxxrraadd is used. Initially, bbooxxrraadd has a value of 0.
A box with rounded corners can be dotted or dashed.
The ..PPSS line can have a second argument specifying a maximum height for
the picture. If the width of zero is specified the width will be
ignored in computing the scaling factor for the picture. Note that GNU
ppiicc will always scale a picture by the same amount vertically as well
as horizontally. This is different from the DWB 2.0 ppiicc which may
scale a picture by a different amount vertically than horizontally if a
height is specified.
Each text object has an invisible box associated with it. The compass
points of a text object are determined by this box. The implicit
motion associated with the object is also determined by this box. The
dimensions of this box are taken from the width and height attributes;
if the width attribute is not supplied then the width will be taken to
be tteexxttwwiidd; if the height attribute is not supplied then the height
will be taken to be the number of text strings associated with the
object times tteexxtthhtt. Initially tteexxttwwiidd and tteexxtthhtt have a value of 0.
In (almost all) places where a quoted text string can be used, an
expression of the form
sspprriinnttff((""format"",, arg,,...))
can also be used; this will produce the arguments formatted according
to format, which should be a string as described in pprriinnttff(3) appropri-
ate for the number of arguments supplied.
The thickness of the lines used to draw objects is controlled by the
lliinneetthhiicckk variable. This gives the thickness of lines in points. A
negative value means use the default thickness: in TeX output mode,
this means use a thickness of 8 milliinches; in TeX output mode with
the -cc option, this means use the line thickness specified by ..ppss
lines; in troff output mode, this means use a thickness proportional to
the pointsize. A zero value means draw the thinnest possible line sup-
ported by the output device. Initially it has a value of -1. There is
also a tthhiicckk[nneessss] attribute. For example,
cciirrccllee tthhiicckknneessss 11..55
would draw a circle using a line with a thickness of 1.5 points. The
thickness of lines is not affected by the value of the ssccaallee variable,
nor by the width or height given in the ..PPSS line.
Boxes (including boxes with rounded corners), circles and ellipses can
be filled by giving them an attribute of ffiillll[eedd]. This takes an
optional argument of an expression with a value between 0 and 1; 0 will
fill it with white, 1 with black, values in between with a proportion-
ally gray shade. A value greater than 1 can also be used: this means
fill with the shade of gray that is currently being used for text and
lines. Normally this will be black, but output devices may provide a
mechanism for changing this. Without an argument, then the value of
the variable ffiillllvvaall will be used. Initially this has a value of 0.5.
The invisible attribute does not affect the filling of objects. Any
text associated with a filled object will be added after the object has
been filled, so that the text will not be obscured by the filling.
Three additional modifiers are available to specify colored objects:
oouuttlliinnee[dd] sets the color of the outline, sshhaaddeedd the fill color, and
ccoolloo[uu]rr[eedd] sets both. All three keywords expect a suffix specifying
the color, for example
cciirrccllee sshhaaddeedd ""ggrreeeenn"" oouuttlliinnee ""bbllaacckk""
Currently, color support isn't available in TeX mode. Predefined color
names for ggrrooffff are in the device macro files, for example ppss..ttmmaacc;
additional colors can be defined with the ..ddeeffccoolloorr request (see the
manual page of ttrrooffff(1) for more details).
To change the name of the vbox in TeX mode, set the pseudo-variable
ffiiggnnaammee (which is actually a specially parsed command) within a pic-
ture. Example:
..PPSS
ffiiggnnaammee == ffoooobbaarr;;
......
..PPEE
The picture is then available in the box \\ffoooobbaarr.
ppiicc assumes that at the beginning of a picture both glyph and fill
color are set to the default value.
Arrow heads will be drawn as solid triangles if the variable aarrrroowwhheeaadd
is non-zero and either TeX mode is enabled or the -nn option has not
been given. Initially aarrrroowwhheeaadd has a value of 1. Note that solid
arrow heads are always filled with the current outline color.
The troff output of ppiicc is device-independent. The -TT option is there-
fore redundant. All numbers are taken to be in inches; numbers are
never interpreted to be in troff machine units.
Objects can have an aalliiggnneedd attribute. This will only work if the
postprocessor is ggrrooppss. Any text associated with an object having the
aalliiggnneedd attribute will be rotated about the center of the object so
that it is aligned in the direction from the start point to the end
point of the object. Note that this attribute will have no effect for
objects whose start and end points are coincident.
In places where ntthh is allowed ``expr''tthh is also allowed. Note that ''tthh
is a single token: no space is allowed between the '' and the tthh. For
example,
ffoorr ii == 11 ttoo 44 ddoo {{
lliinnee ffrroomm ``ii''tthh bbooxx..nnww ttoo ``ii++11''tthh bbooxx..ssee
}}
CCOONNVVEERRSSIIOONN
To obtain a stand-alone picture from a ppiicc file, enclose your ppiicc code
with ..PPSS and ..PPEE requests; rrooffff configuration commands may be added at
the beginning of the file, but no rrooffff text.
It is necessary to feed this file into ggrrooffff without adding any page
information, so you must check which ..PPSS and ..PPEE requests are actually
called. For example, the mm macro package adds a page number, which is
very annoying. At the moment, calling standard ggrrooffff without any macro
package works. Alternatively, you can define your own requests, e.g.
to do nothing:
..ddee PPSS
....
..ddee PPEE
....
ggrrooffff itself does not provide direct conversion into other graphics
file formats. But there are lots of possibilities if you first trans-
form your picture into PostScript(R) format using the ggrrooffff option
-TTppss. Since this ps-file lacks BoundingBox information it is not very
useful by itself, but it may be fed into other conversion programs,
usually named ppss22other or ppssttooother or the like. Moreover, the Post-
Script interpreter gghhoossttssccrriipptt (ggss) has built-in graphics conversion
devices that are called with the option
ggss -ssDDEEVVIICCEE==
Call
ggss --hheellpp
for a list of the available devices.
As the Encapsulated PostScript File Format EEPPSS is getting more and more
important, and the conversion wasn't regarded trivial in the past you
might be interested to know that there is a conversion tool named
ppss22eeppss which does the right job. It is much better than the tool
ppss22eeppssii packaged with ggss.
For bitmapped graphic formats, you should use ppssttooppnnmm; the resulting
(intermediate) PPNNMM file can be then converted to virtually any graphics
format using the tools of the nneettppbbmm package .
FILES //uussrr//sshhaarree//ggrrooffff//11..1199..11//ttmmaacc//ppiicc..ttmmaacc
Example definitions of the PPSS and PPEE macros.
SEE ALSO
ttrrooffff(1), ggrrooffffoouutt(5), tteexx(1), ggss(1), ppss22eeppss(1), ppssttooppnnmm(1),
ppss22eeppssii(1), ppnnmm(5)
Tpic: Pic for TeX
Brian W. Kernighan, PIC - A Graphics Language for Typesetting (User
Manual). AT&T Bell Laboratories, Computing Science Technical Report
No. 116 (revised May,
1991).
ppss22eeppss is available from CTAN mirrors, e.g.
W. Richard Stevens - Turning PIC Into HTML
W. Richard Stevens - Examples of picMacros
BUGS
Input characters that are invalid for ggrrooffff (ie those with ASCII code
0, or 013 octal, or between 015 and 037 octal, or between 0200 and 0237
octal) are rejected even in TeX mode.
The interpretation of ffiillllvvaall is incompatible with the pic in 10th edi-
tion Unix, which interprets 0 as black and 1 as white.
PostScript(R) is a registered trademark of Adobe Systems Incorporation.
Groff Version 1.19.1 9 July 2003 PIC(1)